Memory Management
ST RAM and TT RAM
Atari systems support two kinds of memory. Standard RAM (sometimes referred to as 'ST RAM') is general purpose RAM that can be used for any purpose including video and DMA. Current Atari architecture limits the amount of standard RAM a system may have to 14MB.
Alternative RAM (sometimes referred to as 'TT RAM') can be accessed faster than standard RAM but is not suitable for video memory or DMA transfers.
Allocating and freeing memory
The
Malloc() and
Mxalloc() calls allocate memory blocks from the system heap.
Malloc() chooses the type of memory it allocates based on fields in the
ProgramHeader?.
Mxalloc() allows the application to choose the memory type at run-time.
Memory allocated with either
Malloc() or
Mxalloc() may be returned to the system with
Mfree(). Memory allocated by a process is automatically freed when the process calls
Pterm().
Memory protection
MultiTOS? and
MiNT (when run by 68030 processors or above) use memory protection to prevent an errant process from damaging another. It is possible with
Mxalloc() to dynamically set the protection level of an allocated block.
MagiC? doesn't use memory protection.